import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int q = in.nextInt();
            //读取数组及预处理求和
            int[] a = new int[n + 1];
            long[] dp = new long[n + 1];
            for(int i = 1; i <= n; i++){
                a[i] = in.nextInt();
                dp[i] = dp[i - 1] + a[i];
            }
            //计算查询
            for(int i = 0; i < q; i++){
                int l = in.nextInt();
                int r = in.nextInt();
                System.out.println(dp[r] - dp[l - 1]);
            }
        }
    }
}